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    <meta charset="UTF-8">
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    <title>逻辑中断练习</title>
    <script>
        var num = 0
        console.log(123 || num++);  // 是逻辑或 123为真 则返回123，后面的num++不再执行         123
        console.log(num);// 所以这里的num为0                                                 0
    </script>
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